Hitherto, piezoelectric elements have had a configuration in which a piezoelectric layer made of a piezoelectric material having an electromechanical conversion function is placed between two electrodes. Piezoelectric elements are mounted on liquid ejecting heads or liquid ejecting apparatuses as, for example, a flexure-mode actuator device and are also widely used in ultrasonic measuring apparatuses, various motors, sensors, memory devices and the like. As the piezoelectric material constituting the piezoelectric layer of the piezoelectric element, lead zirconate titanate (PZT) is known as a representative example. However, the development of a piezoelectric material in which the content of lead is suppressed has advanced from the viewpoint of a reduction in an environmental load.
For example, a piezoelectric material which is formed of a mixed crystal of Bi(Fe,Mn)O3 and Ba(Zr,Ti)O3 and expressed by composition formula (1-x)Bi(Fe1-yMny)O3-xBa(ZruTi1-u)O3 where 0<×<0.40, 0.01<y21 0.10, and 0≦u0.16 is proposed (for example, see JP-A-2009-252789).
However, in a piezoelectric material in which the content of lead is suppressed as in PTL 1, it is difficult to suppress a leak current when a predetermined kind of metal is diffused in the electrode. Thus, in recent years in which a further increase in density and performance has been required for liquid ejecting heads, a piezoelectric material capable of reducing a leak current has been required. In addition, an improvement in durability with respect to repetitive application of a voltage is also required for a piezoelectric material, and how to provide a piezoelectric material having excellent reliability is a problem which is expected to be solved. Such a problem is also present not only in piezoelectric materials constituting piezoelectric layers of piezoelectric elements used in liquid ejecting heads, but also in piezoelectric materials constituting piezoelectric layers of piezoelectric elements mounted on other apparatuses including ultrasonic measuring apparatuses.
An object of the invention is to provide a piezoelectric material, a piezoelectric element, a liquid ejecting head, a liquid ejecting apparatus, and an ultrasonic measuring apparatus in which reliability can be improved in view of the circumstances.